Nicotine and a variety of carcinogens are known to contribute to the addictive and adverse health effects of tobacco use. However, the causative agents for many adverse effects of tobacco have not been identified, and additional tobacco or tobacco smoke constituents may contribute. Identifying and studying these additional compounds is important for understanding the mechanisms of tobacco-related disease and addiction, and for assessing the risks of newer modified cigarettes and other tobacco products that are now being marketed. These questions are a specific focus of the University of Minnesota (U of MN) NIDA/NCI-funded Transdisciplinary Tobacco Research Center (TTURC), and the requested instrumentation will substantially expand the scope of the Center's work. The Specific Aim of this proposal is to obtain a TSE Inhalation System to generate cigarette smoke which can be used for the direct exposure of experimental animals to tobacco smoke, for preparation of tobacco condensates for in vitro use, and for quantitation of individual constituents of cigarette smoke. Research projects will include (Project number 1, investigator Hecht) cancer chemoprevention and mechanisms of carcinogenesis, (Project number 2, investigator Murphy) nicotine metabolism, (Project number 3, investigator Pentel) addiction-related behaviors and effects of gestational smoke exposure, (Project number 4, investigator Peterson) neural stem cell differentiation, (Project number 5, investigator Ondrey) upper aerodigestive carcinogenesis, and (Project number 6, investigator Bechtold) bone healing and implant integration. The TSE Inhalation System consists of an automated cigarette smoke generator, mixing and diluting chambers, smoke monitoring instrumentation, and small animal exposure chambers. Smoke characteristics and representative smoke constituents can be monitored and controlled in real time. A core of investigators (Hecht, Murphy, Pentel) with experience in tobacco chemistry and analytical techniques will assist other investigators in obtaining and characterizing tobacco extracts and biological measures of tobacco constituent exposure. The Core Analytical Laboratory of the TTURC will be made available to facilitate these analyses. The TSE system will be housed at MMRF, located 5 minutes from the U of MN, which will provide space and the required facilities modifications. The Pentel laboratory will supervise its operation by a single research assistant who will provide services for the other laboratories, including performing animal exposure experiments, and preparing tobacco condensates which can then be further processed and characterized as needed by the individual laboratories. This instrumentation will considerably expand the capabilities and scope of the specific projects involved.